Lesson 6: Design a 3dB Coupler using VB Script

Defining Materials

To define the materials for the 3dB coupler, perform the following procedure. Step Action 1 Click File > New. The Initial Properties dialog box appears (see Figure 1). Figure 1: Initial Properties dialog box 2 Create the following dielectric material: Name: CladEffInd Refractive index (Re): 1.49 3 To save the material, click Store. 4 Create…

Defining Layout Settings

To define the layout settings, perform the following procedure. Step Action 1 Type the following settings.a.   Waveguide Properties: Width: 4 Profile: WG1 (see Figure 3) Figure 3: Initial Properties dialog box b.   Wafer Dimensions:Length: 1000 Width: 40 (see Figure 4). c.   2D Wafer Properties: Material: CladEffInd (see Figure 5) Figure 4: Wafer Dimensions tab Figure 5: 2D Wafer Properties tab…

Drawing and Positioning the Waveguides

To draw and position the waveguides, perform the following procedure (see Figure 8). Step Action 1 Adjust the zoom to fill the screen. 2 To snap to the grid and to the waveguide: a.   From the Preferences menu, select Layout Options. The Layout Properties dialog box appears. b.   Under Grid, select the Snap to Grid…

Generating the Layout Script

To generate the layout script, perform the following procedure. Step Action 1 Click the Scripting tab in the main project window (see Figure 17). The Scripting window appears. Figure 17:   Scripting tab 2 From the Simulation menu, select Generate Layout Script. A prompt message box appears (see Figure 18). Figure 18:   Prompt message…

Inserting and Editing the Input Plane

To insert and edit the input plane, perform the following procedure. Step Action 1 From the Draw menu, select Input Plane. 2 To insert the input plane, click at the left side of the layout window. The input plane appears. 3 To edit the input plane, from the Edit menu, select Properties. The Input Plane…

Running the Simulation

To run the simulation, perform the following procedure. Step Action 1 From the Simulation menu, select Calculate 2D Isotropic Simulation. The Simulation Parameters dialog box appears. 2 Under Simulation technique, click Simulate As Is (see Figure 23). Figure 23: Simulation Parameters dialog box The simulator output appears as shown in Figure 24. Figure 24: Simulation…

Modifying the Layout Script

To modify the layout script, perform the following procedure. Step Action 1 Click the Scripting tab. The Scripting window appears. 2 Type the following lines at the end of the layout script: Note: The first lines draw the layout, and the above lines enter a loop. The layout is adjusted to move the coupler waveguides…

Viewing Results in the BPM Analyzer

To view the simulation results in OptiBPM_Analyzer, perform the following procedure. Step Action 1 In the OptiBPM_Analyzer project directory, click Power In Output Waveguides. A graph appears and displays the power in each output waveguide as a function of iteration number. It is clear the optimum design can be found somewhere between the 3rd and 4th…